Semiconductor die assemblies with decomposable materials and associated methods and systems

ABSTRACT

Semiconductor die assemblies with decomposable materials, and associated methods and systems are disclosed. In an embodiment, a semiconductor die assembly includes a memory controller die carrying one or more memory dies attached to its first side. The semiconductor die assembly also includes a biodegradable structure attached to its second side opposite to the first side. The biodegradable structure includes a conductive material and an insulating material, both of which are biodegradable and disintegrate in a wet process. The biodegradable structure can be configured to couple the memory controller die with an interface die. In this manner, when the biodegradable structure disintegrates (e.g., dissolve) in the wet process, the memory controller carrying the memory dies can be separated from the interface die to reclaim the memory controller with the memory dies and the interface die.

TECHNICAL FIELD

The present disclosure generally relates to semiconductor deviceassemblies, and more particularly relates to semiconductor deviceassemblies with decomposable materials and associated methods andsystems.

BACKGROUND

Semiconductor packages typically include one or more semiconductor dies(e.g., memory chips, microprocessor chip, imager chip) mounted on apackage substrate and encased in a protective covering. Thesemiconductor die may include functional features, such as memory cells,processor circuits, or imager devices, as well as bond pads electricallyconnected to the functional features. The bond pads can be electricallyconnected to corresponding conductive structures of the packagesubstrate, which may be coupled to terminals outside the protectivecovering such that the semiconductor die can be connected to higherlevel circuitry.

In some semiconductor packages, two or more semiconductor dies arestacked on top of each other to reduce the footprint of thesemiconductor packages. The semiconductor dies in the stack may bearranged in a pattern resembling stair-steps (which may be referred toas “shingle stacking”) such that a portion of the semiconductor dies maybe freely accessible—e.g., to attach bond wires to one or more bond padslocated in the portion. In some cases, the semiconductor dies may bestacked in a “zig-zag” pattern to increase a space above the bond padswith respect to a semiconductor die overlying above the bond pads so asto facilitate forming the bond wires. In other cases, edges of thesemiconductor dies are aligned to each other to minimize the areaoccupied by the stack. In such cases, the semiconductor dies may beconnected to each other using through-substrate vias (TSVs).

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present technology can be better understood withreference to the following drawings. The components in the drawings arenot necessarily to scale. Instead, emphasis is placed on clearlyillustrating the overall features and the principles of the presenttechnology.

FIGS. 1A and 1B illustrate schematic diagrams of semiconductor dieassemblies in accordance with embodiments of the present technology.

FIG. 2 illustrates a schematic diagram of a system includingsemiconductor die assemblies in accordance with embodiments of thepresent technology.

FIGS. 3A-3C illustrate schematic diagrams of systems includingsemiconductor die assemblies in accordance with embodiments of thepresent technology.

FIG. 4 is a block diagram schematically illustrating a system includinga semiconductor die assembly in accordance with embodiments of thepresent technology.

DETAILED DESCRIPTION

Specific details of several embodiments of semiconductor die assemblieswith decomposable materials, and associated methods and systems aredescribed below. The term “semiconductor device or die” generally refersto a solid-state device that includes one or more semiconductormaterials. Examples of semiconductor devices (or dies) include logicdevices or dies, memory devices or dies, interface devices or dies,controllers, memory controllers, or processors (e.g., central processingunit (CPU), graphics processing unit (GPU)), field-programmable gatearrays (FPGAs), among others.

Such semiconductor devices or dies may include integrated circuits orcomponents, data storage elements, processing components, and/or otherfeatures manufactured on semiconductor substrates. Further, the term“semiconductor device or die” can refer to a finished device or to anassembly or other structure at various stages of processing beforebecoming a finished functional device. Depending upon the context inwhich it is used, the term “substrate” may include a semiconductorwafer, a semiconductor substrate, a package substrate, an interposer, asemiconductor device or die, or the like. Suitable steps of the methodsdescribed herein can be performed with processing steps associated withfabricating semiconductor devices (wafer-level and/or die-level) and/ormanufacturing semiconductor packages.

Modern electronic apparatuses or electronic devices (e.g., workstations,servers, desktop computers, laptop computers, tablets, cell phones,personal digital assistants) generally include a variety of packages ofsemiconductor dies. The semiconductor packages are difficult to recycleand tend to become electronic waste (e-waste) when the electronicapparatuses or devices are no longer in use or discarded. Conventionalsemiconductor packages include, in addition to various kinds ofsemiconductor dies, interconnects (e.g., solder materials, conductivepads, conductive pillars) connecting the semiconductor dies and moldingcompounds encapsulating the semiconductor dies. Such interconnectsinclude materials like aluminum, copper, tin, lead, silver, bismuth,indium, zinc, antimony, among others. The molding compounds includeepoxy resins, phenolic hardeners, silicas, catalysts, pigments, moldrelease agents, or the like.

The conventional molding compounds or interconnect materials are hard toremove to disassemble various components of the semiconductor packages(e.g., memory dies connected to memory controller dies, processor diesconnected to the memory controller dies carrying memory dies). In someinstances, removal of the molding compounds or interconnect materialsgenerates hazardous (or toxic) by-products to humans or naturalenvironments. Moreover, the molding compounds or interconnect materialsare not easily biodegradable (or compostable) in nature once they becomee-waste.

The present technology provides for utilizing decomposable materials forsemiconductor die assemblies (e.g., packages of semiconductor dies,semiconductor packages) or for electronic systems including thesemiconductor die assemblies. The decomposable materials arebiodegradable (or compostable) to reduce electronic waste when thesemiconductor die assemblies (or the systems including semiconductor dieassemblies) are discarded. Further, the decomposable materials arerelatively easy to remove (e.g., easily disintegrate than the moldingcompounds or the interconnect materials described above) such thatcomponents of the semiconductor die assemblies can be disassembledwithout difficulties. For instance, when subject to certain wet chemicalprocess steps, the decomposable materials can dissolve (e.g.,disintegrate, break up, separate) in the wet process. Further, duringthe wet process, the decomposable materials may turn into non-toxicsubstances such that the disassembly processes do not generate toxic (orhazardous) by-products to humans or to the natural environments.

The reclaimed components (or reclaimed semiconductor die assemblies) maybe recycled in a variety of electronic systems. For example, thereclaimed components or semiconductor die assemblies include memorycomponents including one or more memory dies connected to a memorycontroller die (or a logic die). In this regard, such memory componentsmay be examples of or include aspects of high-bandwidth memory (HBM),hybrid memory cube (HMC), semiconductor modules for the compute expresslink (CXL) applications, or systems in package (SIPs).

In some embodiments, the reclaimed memory components may be re-purposedin a system that implements a memory hierarchy different than atraditional memory hierarchy based on performance criteria of the memorycomponents, such as access time. Namely, the memory hierarchy may bebased on lifetimes (or reliability criteria) of the reclaimed memorycomponents (rather than their performance criteria). For example, thememory component with the shortest lifetime (or worst reliabilityparameters) in the system may define the reuse process—e.g., determiningwhether the system needs to be disassembled to reclaim other componentsin the system.

In some embodiments, the systems utilizing reclaimed memory components(or reclaimed semiconductor die assemblies) have relatively relaxedspecifications (or requirements for the reclaimed memory components tosatisfy)—e.g., a less storage capacity than the original storagecapacity, increased access time or latency, increased power consumption,operating under slower clock speeds, or the like. In some embodiments,the systems including reclaimed memory components are designed for lessdemanding applications such as toys, robots for hobbies, non-criticalsensors or timers, to name a few. In other words, the reclaimed memorycomponents may not be deployed in mission-critical applications such asdata centers, autonomous driving systems, medical equipment, or thelike.

As used herein, the terms “front,” “back,” “vertical,” “lateral,”“down,” “up,” “top,” “bottom,” “upper,” and “lower” can refer torelative directions or positions of features in the semiconductor deviceassemblies in view of the orientation shown in the Figures. For example,“upper” or “uppermost” can refer to a feature positioned closer to thetop of a page than another feature. These terms, however, should beconstrued broadly to include semiconductor devices having otherorientations. Unless stated otherwise, terms such as “first” and“second” are used to arbitrarily distinguish between the elements suchterms describe. Thus, these terms are not necessarily intended toindicate temporal or other prioritization of such elements.

FIG. 1A illustrates a schematic diagram of a semiconductor die assembly101 in accordance with embodiments of the present technology. Thesemiconductor die assembly 101 includes a first semiconductor die 110that has a first side 111 and a second side 112 opposite to the firstside 111. The semiconductor die assembly 101 also includes one or moresecond semiconductor dies 115 (also identified individually assemiconductor dies 115 a through 115 d) attached to the first side 111.The second semiconductor dies 115 are operatively coupled to the firstsemiconductor die 110—e.g., using through-substrate vias (TSVs) 120(also identified individually as TSVs 120 a and 120 b). In someembodiments, the first semiconductor die 110 is a memory controller die(or a logic die) and the second semiconductor dies 115 are DRAM dies (orNOT-AND (NAND) memory dies). Further, the DRAM die coupled to the firstsemiconductor die 110 (e.g., the second semiconductor die 115 d) may bereferred to as a master DRAM die while the other DRAM dies (e.g., thesecond semiconductor dies 115 a-c) may be referred to as slave DRAMdies. As shown in FIG. 1A, the topmost second semiconductor die (e.g.,the second semiconductor die 115 a) does not include TSVs 120. In someembodiments, the topmost second semiconductor die (e.g., the secondsemiconductor die 115 a) may be thicker than the other secondsemiconductor dies (e.g., the second semiconductor dies 115 b-d).

Moreover, in the embodiment illustrated in FIG. 1A, the semiconductordie assembly 101 includes a biodegradable structure 125 attached to thesecond side 112 of the first semiconductor die 110. The biodegradablestructure 125 may be configured to easily disintegrate (e.g., dissolve,break up, separate) when subject to certain wet chemical process steps(e.g., in a wet process). In this regard, the biodegradable structure125 includes a conductive material and an insulating material, both ofwhich are biodegradable and disintegrate in the wet process. Further,the biodegradable structure 125 can turn into non-toxic substances inthe wet process. In some embodiments, the biodegradable conductivematerials includes melanin, polyacetylene, polystyrene sulfonate(PEDOT), polyaniline (PANI), polycationic polymer (PPy),3-hexylthiophene (P3HT), or a combination thereof. In some embodiments,the biodegradable insulating material includes polylactic acid (PLA)with cellulose acetate (CA), zinc pyrophosphate (ZnPP), polyurethane(PU) with CA, or a combination thereof.

The conductive material in the biodegradable structure 125 can bearranged to form conductive traces such that the first semiconductor die110 can be connected to the conductive traces of the biodegradablestructure 125. In some embodiments, the TSVs 120 can be connected to theconductive traces of the biodegradable structure 125 throughinterconnects 140 (also identified individually as interconnects 140a/b). In some embodiments, the interconnects 140 includes thebiodegradable conductive materials. In this manner, the conductivetraces of the biodegradable structure 125 provide for the firstsemiconductor die 110 (and for the second semiconductor dies 115)electrical connections to another semiconductor die (e.g., a thirdsemiconductor die, an interface die 220 depicted in FIG. 2 ). In someembodiments, such electrical connections are done at a sidewall 126 ofthe biodegradable structure 125. In this regard, the sidewall 126 of thebiodegradable structure 125 includes one or more portions of theconductive traces exposed to connect with corresponding bond pads of thethird semiconductor die.

FIG. 1A also includes a diagram 103 illustrating an embodiment of thebiodegradable structure 125 configured to couple the first semiconductordie 110 to a third semiconductor die at its sidewall 126. The conductivetraces of the biodegradable structure 125 has first exposed portions 130(also identified individually as 130 a-c) at the sidewall 126. Each ofthe first exposed portions 130 (exposed from the biodegradableinsulating material 135) can be configured to connect to a correspondingbond pad of the third semiconductor die. Additionally, the conductivetraces of the biodegradable structure 125 has second exposed portions131 (also identified individually as 131 a-c) at a surface 127 of thebiodegradable structure 125. Each of the second exposed portions 131 canbe configured to connect to a corresponding TSVs 120—i.e., theconductive material of the biodegradable structure 125 is operativelycoupled to the first semiconductor die 110. In this manner, each of theconductive traces of the biodegradable structure 125 can couple the TSVsconnected to the first semiconductor die 110 with corresponding bondpads of the third semiconductor die.

The semiconductor die assembly 101 may further include an encapsulatingstructure 145. In some embodiments, the encapsulating structure 145includes the same biodegradable insulating material as the biodegradablestructure 125. In other embodiments, the encapsulating structure 145includes a biodegradable insulating material different than thebiodegradable insulating material of the biodegradable structure 125.For example, the insulating material of the encapsulating structure 145has a slower removal rate in the wet process than the biodegradableinsulating material of the biodegradable structure 125. In this manner,when the insulating material of the biodegradable structure 125 hasdisintegrated (e.g., dissolved) in the wet process, the insulatingmaterial of the encapsulating structure 145 still remains to protect thefirst semiconductor die 110 and the second semiconductor dies 115. Inyet another embodiments, the encapsulating structure 145 includes aconventional molding material described above. In a particular aspect ofan embodiment shown in FIG. 1A, the encapsulating structure 145 enclosesthe first semiconductor die 110. As such, the first semiconductor die110 communicates with a third semiconductor die (e.g., the interface die220) through the biodegradable structure 125.

FIG. 1B illustrates a schematic diagram of a semiconductor die assembly102 in accordance with embodiments of the present technology. Thesemiconductor die assembly 102 includes aspects of the semiconductor dieassembly 101 described above. For example, the semiconductor dieassembly 102 includes the first semiconductor die 110 carrying the stackof second semiconductor dies 115. Further, the semiconductor dieassembly 102 includes the biodegradable structure 125.

In a particular aspect of an embodiment shown in FIG. 1B, theencapsulating structure 145 partially encloses the first semiconductordie 110. In other words, the first semiconductor die 110 includes aporch 155 extending out of the encapsulating structure 145. Moreover,the porch has one or more bond pads 150 (also identified individually asbond pads 150 a/b) configured to couple to corresponding bond pads of athird semiconductor die (e.g., the interface die 220). In this manner,the first semiconductor die 110 can directly communicate with the thirdsemiconductor die. In some embodiments, the direct communication pathsbetween the first semiconductor die 110 and the third semiconductor die220 facilitate faster signal transmission between the two semiconductordies—e.g., when compared to the communication paths through thebiodegradable structure 125.

FIG. 2 illustrates a schematic diagram of a system 200 includingsemiconductor die assemblies 101 and 102 in accordance with embodimentsof the present technology. The system 200 includes a printed circuitboard (PCB) 210, interface dies 220 (also identified individually asinterface dies 220 a/b) attached to the PCB 210. Each of the interfacedies 220 has a surface opposite to the PCB 210, to which thesemiconductor die assembly (e.g., the semiconductor die assembly 101 or102) is attached. In some embodiments, the interface dies 220 includeprocessors (e.g., arithmetic logic units (ALUs), GPUs) or other suitablesemiconductor dies serving the purpose of the system 200. In someembodiments, the interface die 220 is configured to control analoginput/output (I/O) signals (e.g., control signals, power signals) andthe first semiconductor die 110 is configured to control logic I/Osignals for the system 200. In some embodiments, the semiconductor dieassembly 101 or 102 includes aspects of HBM, HMC, modules for CXLapplications, or SIPs. In some embodiments, the interface die 220includes aspects of GPUs or CPUs.

The interface dies 220 can be attached to the PCB 210 usinginterconnects 215. In some embodiments, the interconnects 215 includeball grid array (BGA) with conventional interconnect materials. In otherembodiments, the interconnects 215 include one or more of thebiodegradable conductive materials. Moreover, the system 200 includes anencapsulating structure 240 on the PCB 210, which is configured toenclose the interface dies 220 and the semiconductor die assemblies101/102. In some embodiments, the encapsulating structure 240 includesone or more of the biodegradable insulating materials.

As described with reference to the diagram 103 of FIG. 1A, thebiodegradable structures 125 of the semiconductor die assemblies 101/102are configured to attached to bond pads 225 (e.g., the bond pads 225 aand 225 b) of the interface dies 220, respectively. For example, thebiodegradable structure 125 a is attached to the bond pad 225 a of theinterface die 220 a at its sidewall facing the interface die 220 a. Inthis regard, the exposed portion 130 at the sidewall 126 of thebiodegradable structure 125 a are bonded to (attached to) the bond pad225 a of the interface die 220 a—i.e., the conductive material of thebiodegradable structure 125 a is operatively coupled to the interfacedie 220 a. Although the cross-sectional illustration of thesemiconductor die assembly 200 shows a single bond pad 225 a of theinterface die 220 a, it should be understood that the interface die 220a may include multiple bond pads, each of them coupled to acorresponding exposed portion 130 of the conductive traces of thebiodegradable structure 125 a.

In some embodiments, the exposed portion 130 directly attaches to thebond pad 225 a in response to thermal energy applied to the exposedportion 130 and the bond pad 225 a in close proximity—e.g., a directbonding scheme. In other embodiments, a soldering material (not shown)or a biodegradable conductive material is used to facilitate bondingbetween the exposed portion 130 and the bond pad 225 a. In this manner,the first semiconductor die 110 (and the second semiconductor dies 115operatively coupled to the first semiconductor die 110) can communicatewith the interface die 220 through the biodegradable structure 125—e.g.,communication paths (or channels) or data paths (or channels) configuredto transmit and receive signals and/or data between the interface die220 and the first semiconductor die 110 (and the second semiconductordies 115 operatively coupled to the first semiconductor die 110).Further, as illustrated in FIG. 2 , the first and second semiconductordies 110 and 115 are arranged generally perpendicular to the interfacedie 220.

Similarly, the semiconductor die assembly 102 is attached to theinterface die 220 b through the biodegradable structure 125 b. Namely,the biodegradable structure 125 b is attached to the bond pad 225 b ofthe interface die 220 b at its sidewall facing the interface die 220 bas described above with respect to the biodegradable structure 125 aattached to the bond pad 225 a of the interface die 220 a. Further, thesemiconductor die assembly 102 includes the first semiconductor die 110b with the porch 155 out of the incapsulating structure 145 b. The porchincludes bond pads 150 a/b of the first semiconductor die 110 b. In someembodiments, a bond wire 230 couples the bond pad 150 a of the firstsemiconductor die 110 b to the bond pad 225 d of the interface die 220b. Additionally, or alternatively, a conductive pillar structure 235 maycouple the bond pad 150 b of the first semiconductor die 110 b to thebond pad 225 c of the interface die 220 b.

In this manner, the first semiconductor die 110 b can communicatedirectly with the interface die 220 b in addition to the communicationpaths established through the biodegradable structure 125 b. Such directcommunication paths may facilitate high-speed signal or datatransmission between the interface die 220 b and the first semiconductordie 110 b (and the second semiconductor dies 115 operatively coupled tothe first semiconductor die 110 b)—e.g., high-speed data paths (orchannels), high-speed signal paths (or channels).

In view of the semiconductor die assembly 101 (or 102) stacked on top ofthe interface die 220, the system 200 has a footprint that is less thanthat of a system having the semiconductor die assembly and the interfacedie 220 disposed side-by-side. In some embodiments, the interface die220 corresponds to a GPU and the semiconductor die assembly 101 (or 102)corresponds to an HBM including an HBM controller (e.g., the firstsemiconductor die 110) carrying one or more DRAM dies (e.g., the secondsemiconductor dies 115). The GPU may communicate with the HBM controllerthrough the biodegradable structure 125 to access (e.g., read or writedata) the DRAM dies. If the system 200 supports high-speed data transferrates to access the DRAM dies, the GPU may directly communicate with theHBM controller through the high-speed data paths established betweenthem—e.g., the bond pads of the GPU directly connected to the bond padsof the HBM controller.

Moreover, the semiconductor die assembly 101 (or 102) can be easilydisassembled from the system 200 because the semiconductor die assembly101 (or 102) is attached to the interface die 220 through thebiodegradable structure 125. For example, the encapsulating structure240 including the biodegradable insulating materials can be removed in awet process. Subsequently, the biodegradable structure 125 disintegratesin the wet process, thereby releasing the semiconductor die assembly 101(or 102) from the interface die 220. Further, if the interconnects 215are made of the biodegradable conductive materials, the interface die220 can be released from the PCB 210 in the wet process. In this manner,the biodegradable materials can facilitate separating components of thesystem 200 such that the reclaimed components (e.g., the semiconductordie assembly 101/102, the interface dies 220 a/b) can be recycledinstead of becoming e-waste. Even if the system 200 is discarded, thebiodegradable materials of the system 200 (e.g., the biodegradablecontents of the system 200) are expected to reduce the total amount ofe-waste.

Although the system 200 of FIG. 2 includes two semiconductor dieassemblies 101 and 102 for illustration purposes only (e.g., to describetwo different ways of establishing communication paths between the firstsemiconductor die 110 and the interface die 220), the present technologyis not limited thereto. For example, the system may include onesemiconductor die assembly (the semiconductor die assembly 101 or thesemiconductor die assembly 102) attached to a single interface die 220.In another example, the system may include three (3), four (4), orgreater quantities of semiconductor die assemblies (and correspondinginterface dies). In some embodiments, all the semiconductor dieassemblies of the system include same kinds of second semiconductor dies115—e.g., memory dies (e.g., DRAM dies, NAND memory dies). In otherembodiments, the semiconductor die assemblies of the system may includedifferent kinds of memory dies as the second semiconductor dies 115(e.g., one or more including DRAM dies, others including NAND memorydies).

FIG. 3A illustrates a schematic diagram of a system 301 includingsemiconductor die assemblies 101 and/or 102 in accordance withembodiments of the present technology. The system 301 includes aspectsof the system 200 described with reference to FIG. 2 . For example, thesystem 301 includes semiconductor die assemblies 101 a/b and/or 102 a/battached to the interface dies 220 a/b. Details of the connectionschemes between the semiconductor die assembly 101/102 and the interfacedie 220 described with reference to FIG. 2 (e.g., the biodegradablestructure 125 attached to the bond pad 225 of the interface die 220 atits sidewall facing the interface die 220, the bond pads 150 of thefirst semiconductor die 110 directly coupled to the bond pads 225 of theinterface die 220) are omitted in the diagram of the system 301 for aclear illustration of overall features and principles of the presenttechnology. Also, the encapsulating structures 145 of the semiconductordie assemblies 101/102 are omitted.

The system 301 includes a first deck 310 (a lower deck, a bottom deck)having two semiconductor die assemblies (e.g., the semiconductor dieassemblies 101 a/b and/or 102 a/b) and a second deck 315 (an upper deck,a top deck) having two semiconductor die assemblies (e.g., thesemiconductor die assemblies 101 c/d and/or 102 c/d). The system 301includes an encapsulating structure 340 on the PCB 210, which isconfigured to enclose the interface dies 220 and the semiconductor dieassemblies 101/102 of both decks. In some embodiments, the encapsulatingstructure 340 includes the biodegradable insulating materials.

In some embodiments, the interface die of the upper deck (e.g., theinterface die 220 c) relays signals from the semiconductor die assemblyof the upper deck (e.g., semiconductor die assembly 101 c/102 c) to theinterface die of the lower deck (e.g., the interface die 220 a) throughthe biodegradable structure 125 a. As such, the biodegradable structure125 a may be configured to communicate signals with the interface die220 c at its top sidewall attached to the interface die 220 c (oppositeto its bottom sidewall attached to the interface die 220 a). Further,the interface die 220 c may be configured to include bond pads at itsboth surfaces (e.g., top and bottom surfaces) such that thebiodegradable structure 125 c can be attached to the bond pads facingthe biodegradable structure 125 c (at its top surface) and thebiodegradable structure 125 a can be attached to the bond pads facingthe biodegradable structure 125 a (at its bottom surface).

FIG. 3B illustrates a schematic diagram of a system 302 includingsemiconductor die assemblies 101 and/or 102 in accordance withembodiments of the present technology. As with the system 301, thesystem 302 includes aspects of the system 200 described with referenceto FIG. 2 —e.g., semiconductor die assemblies 101 a/b and/or 102 a/battached to the interface dies 220 a/b. Further, the system 302 includesthe first and second decks 310 and 315. As such, the system 302 may beregarded as a variation of the system 301 with certain differences.

For example, the system 302 does not include interface dies for thesemiconductor die assemblies of the upper deck 315 (i.e., the interfacedies 220 c/d of the system 301 are omitted). Instead, the interface diesof the lower deck 310 (e.g., the interface dies 220 a/b) access thesemiconductor die assemblies 101 c/d and/or 102 c/d through verticalbiodegradable structures 345 (also identified individually as verticalbiodegradable structures 345 a/b) attached to the interface dies 220 a/bof the lower deck 310. The vertical biodegradable structures 345 extendfrom the surface of the interface dies 220 a/b to a height (denoted asH2) greater than the height (denoted as H1) of the semiconductor dieassemblies 101 a/b and/or 102 a/b of the lower deck 310. Further, thevertical biodegradable structures 345 can be configured similarly to thebiodegradable structures 125. Namely, the vertical biodegradablestructures 345 may be configured to easily disintegrate in a wetprocess. Moreover, the vertical biodegradable structures 345 include theconductive material and the insulating material, both of which arebiodegradable and disintegrate in the wet process.

The conductive material in the vertical biodegradable structures 345 canbe arranged to form conductive traces such that the conductive traces ofthe biodegradable structures of the upper deck semiconductor dieassemblies can be connected to the conductive traces of the verticalbiodegradable structure 345 appropriately. For example, the conductivetraces of the biodegradable structure 125 c of the semiconductor dieassemblies 101 c/102 c can be connected to the conductive traces of thevertical biodegradable structure 345 a appropriately, and the conductivetraces of the vertical biodegradable structure 345 a are connected tothe bond pads of the interface die 220 a. In this manner, the verticalbiodegradable structures 345 can provide signal paths (e.g.,communication paths, data paths) between the first semiconductor dies110 c/d (and the second semiconductor dies 115 operatively coupled tothe first semiconductor dies 110 c/d) of the upper deck 315 and theinterface dies 220 a/b of the lower deck 310.

FIG. 3C illustrates a schematic diagram of a system 303 includingsemiconductor die assemblies 101 and/or 102 in accordance withembodiments of the present technology. As with the systems 301 and 302,the system 303 includes aspects of the system 200 described withreference to FIG. 2 —e.g., semiconductor die assemblies 101 a/b and/or102 a/b attached to the interface dies 220 a/b. Further, the system 303includes the first and second decks 310 and 315. As such, the system 303may be regarded as another variation of the systems 301 and 302 withcertain differences.

For example, as with the system 302, the system 303 does not includeinterface dies for the semiconductor die assemblies of the upper deck315. Further, the system 303 does not include the vertical biodegradablestructures 345 of the system 302. Instead, the biodegradable structures125 of the lower deck semiconductor die assemblies 101 a/b (or 102 a/b)extend to the upper deck 315 such that the conductive traces of thebiodegradable structures 125 of the lower deck semiconductor dieassemblies 101 a/b (or 102 a/b) can be connected to the conductivetraces of the biodegradable structures 125 of the upper decksemiconductor die assemblies 101 c/d (or 102 c/d) appropriately. By wayof example, the conductive traces of the biodegradable structure 125 acan be connected to the conductive traces of the biodegradable structure125 c. In this manner, the combination of the biodegradable structures125 (e.g., the combination of the biodegradable structures 125 a and 125c) can provide signal paths (e.g., communication paths, data paths)between the first semiconductor dies 110 c/d (and the secondsemiconductor dies 115 operatively coupled to the first semiconductordies 110 c/d) of the upper deck 315 and the interface dies 220 a/b ofthe lower deck 310.

Although forgoing example embodiments of the systems 301 through 303includes two decks of semiconductor die assemblies for illustrationpurposes, the present technology is not limited thereto. For example,the systems in accordance with the present technology may include three(3), four (4), five (5), or even greater quantities of decks. Moreover,although the example embodiments of the systems 301 through 303 includestwo semiconductor die assemblies per deck for illustration purposes, inother embodiments, each deck may include one (1) semiconductor dieassembly or more than two semiconductor die assemblies—e.g., three (3),four (4), or even greater quantities of semiconductor die assemblies.

FIG. 4 is a block diagram schematically illustrating a system 400including a semiconductor die assembly in accordance with embodiments ofthe present technology. The system 400 may be an example of or includeaspects of the systems 200, 301, 302, or 303 described with reference toFIGS. 2, and 3A-3C. The system 400 can include a semiconductor deviceassembly 470, a power source 472, a driver 474, a processor 476, and/orother subsystems or components 478. The semiconductor die assembly 101or 102 described with reference to FIGS. 1A and 1B may be included inthe semiconductor device assembly 470 of the system 400.

The semiconductor device assembly 470 can have features generallysimilar to the semiconductor die assembly 101 or 102 described abovewith reference to FIGS. 1A and 1B. For example, the semiconductor deviceassembly 470 includes a first semiconductor die including a first sideand a second side opposite to the first side, one or more secondsemiconductor dies attached to the first side, the one or more secondsemiconductor dies operatively coupled to the first semiconductor die,and a biodegradable structure attached to the second side, thebiodegradable structure configured to disintegrate in a wet process,where the biodegradable structure includes a conductive material and aninsulating material, both of which are biodegradable and disintegrate inthe wet process.

The system 400 can have features generally similar to the system 200,301-303 described above with reference to FIGS. 2 and 3A-3C. Forexample, the system 400 includes a printed circuit board (PCB) and aninterface die attached to the PCB, the interface die having a surfaceopposite to the PCB. The system 400 further includes a semiconductor dieassembly attached to the surface, where the semiconductor die assemblyincludes a memory controller die having a first side and a second sideopposite to the first side, one or more memory dies attached to thefirst side, the one or more memory dies operatively coupled to thememory controller die, and a biodegradable structure attached to thesecond side, the biodegradable structure configured to disintegrate in awet process, where the biodegradable structure includes a conductivematerial and an insulating material, both of which are biodegradable anddisintegrate in the wet process.

The resulting system 400 can perform any of a wide variety of functions,such as memory storage, data processing, and/or other suitablefunctions. Accordingly, representative systems 400 can include, withoutlimitation, hand-held devices (e.g., mobile phones, tablets, digitalreaders, and digital audio players), computers, and appliances.Components of the system 400 may be housed in a single unit ordistributed over multiple, interconnected units (e.g., through acommunications network). The components of the system 400 can alsoinclude remote devices and any of a wide variety of computer readablemedia.

It should be noted that the methods described above describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Furthermore, embodiments from two or more of the methods may becombined. From the foregoing, it will be appreciated that specificembodiments of the technology have been described herein for purposes ofillustration, but that various modifications may be made withoutdeviating from the disclosure. In addition, while in the illustratedembodiments certain features or components have been shown as havingcertain arrangements or configurations, other arrangements andconfigurations are possible. Moreover, certain aspects of the presenttechnology described in the context of particular embodiments may alsobe combined or eliminated in other embodiments.

The devices discussed herein, including a semiconductor device, may beformed on a semiconductor substrate or die, such as silicon, germanium,silicon-germanium alloy, gallium arsenide, gallium nitride, etc. In somecases, the substrate is a semiconductor wafer. In other cases, thesubstrate may be a silicon-on-insulator (SOI) substrate, such assilicon-on-glass (SOG) or silicon-on-sapphire (SOS), or epitaxial layersof semiconductor materials on another substrate. The conductivity of thesubstrate, or sub-regions of the substrate, may be controlled throughdoping using various chemical species including, but not limited to,phosphorous, boron, or arsenic. Doping may be performed during theinitial formation or growth of the substrate, by ion-implantation, or byany other doping means.

As used herein, including in the claims, “or” as used in a list of items(for example, a list of items prefaced by a phrase such as “at least oneof” or “one or more of”) indicates an inclusive list such that, forexample, a list of at least one of A, B, or C means A or B or C or AB orAC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase“based on” shall not be construed as a reference to a closed set ofconditions. For example, an exemplary step that is described as “basedon condition A” may be based on both a condition A and a condition Bwithout departing from the scope of the present disclosure. In otherwords, as used herein, the phrase “based on” shall be construed in thesame manner as the phrase “based at least in part on.” The term“exemplary” used herein means “serving as an example, instance, orillustration,” and not “preferred” or “advantageous over otherexamples.”

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thescope of the invention. Rather, in the foregoing description, numerousspecific details are discussed to provide a thorough and enablingdescription for embodiments of the present technology. One skilled inthe relevant art, however, will recognize that the disclosure can bepracticed without one or more of the specific details. In otherinstances, well-known structures or operations often associated withmemory systems and devices are not shown, or are not described indetail, to avoid obscuring other aspects of the technology. In general,it should be understood that various other devices, systems, and methodsin addition to those specific embodiments disclosed herein may be withinthe scope of the present technology.

What is claimed is:
 1. A semiconductor die assembly, comprising: a firstsemiconductor die including a first side and a second side opposite tothe first side; one or more second semiconductor dies attached to thefirst side, the one or more second semiconductor dies operativelycoupled to the first semiconductor die; and a biodegradable structureattached to the second side, the biodegradable structure including aconductive material operatively coupled to the first semiconductor dieand an insulating material, wherein both the conductive material and theinsulating material are biodegradable and configured to disintegrate ina wet process.
 2. The semiconductor die assembly of claim 1, wherein theconductive material forms conductive traces arranged to operativelycouple the first semiconductor die to a third semiconductor die at asidewall of the biodegradable structure.
 3. The semiconductor dieassembly of claim 2, wherein the sidewall includes one or more portionsof the conductive traces exposed to connect with corresponding bond padsof the third semiconductor die.
 4. The semiconductor die assembly ofclaim 2, wherein the first semiconductor die carrying the one or moresecond semiconductor dies separates from the third semiconductor die asa result of the wet process.
 5. The semiconductor die assembly of claim1, wherein the biodegradable structure turns into a non-toxic substancein the wet process.
 6. The semiconductor die assembly of claim 1,wherein: the conductive material includes melanin, polyacetylene,polystyrene sulfonate (PEDOT), polyaniline (PANI), polycationic polymer(PPy), 3-hexylthiophene (P3HT), or a combination thereof; and theinsulating material includes polylactic acid (PLA) with celluloseacetate (CA), zinc pyrophosphate (ZnPP), polyurethane (PU) with CA, or acombination thereof.
 7. The semiconductor die assembly of claim 1,further comprising: an encapsulating structure on the biodegradablestructure, wherein the encapsulating structure encloses at least aportion of the first semiconductor die, and wherein the encapsulatingstructure includes the biodegradable insulating material.
 8. Thesemiconductor die assembly of claim 7, wherein the first semiconductordie includes a porch extending out of the encapsulating structure, theporch having one or more bond pads configured to couple to correspondingbond pads of a third semiconductor die.
 9. The semiconductor dieassembly of claim 1, wherein: the first semiconductor die includes amemory controller die; and the one or more second semiconductor diesinclude one or more memory dies.
 10. A system, comprising: a printedcircuit board (PCB); an interface die attached to the PCB, the interfacedie having a surface opposite to the PCB; and a semiconductor dieassembly attached to the surface, wherein the semiconductor die assemblyincludes: a memory controller die having a first side and a second sideopposite to the first side; one or more memory dies attached to thefirst side, the one or more memory dies operatively coupled to thememory controller die; and a biodegradable structure attached to thesecond side, the biodegradable structure including a conductive materialoperatively coupled to the memory controller die and an insulatingmaterial, wherein both the conductive material and the insulatingmaterial are biodegradable and configured to disintegrate in a wetprocess.
 11. The system of claim 10, wherein the conductive materialforms conductive traces arranged to operatively couple the memorycontroller die to the interface die at a sidewall of the biodegradablestructure.
 12. The system of claim 11, wherein the sidewall of thebiodegradable structure includes one or more portions of the conductivetraces exposed, and wherein the exposed portions of the conductivetraces are connected to corresponding bond pads of the interface die.13. The system of claim 10, wherein the first and second sides of thememory controller die are perpendicular to the surface of the interfacedie.
 14. The system of claim 10, wherein the semiconductor die assemblyincludes an encapsulating structure enclosing at least a portion of thememory controller die, and wherein the encapsulating structure includesthe insulating material.
 15. The system of claim 14, wherein the memorycontroller die includes a porch extending out of the encapsulatingstructure, the porch having one or more bond pads coupled tocorresponding bond pads of the interface die.
 16. The system of claim10, further comprising: an encapsulating structure on the PCB, theencapsulating structure configured to enclose the interface die and thesemiconductor die assembly, wherein the encapsulating structure includesthe biodegradable insulating material.
 17. The system of claim 10,wherein the interface die is a first interface die, the semiconductordie assembly is a first semiconductor die assembly, and the systemfurther comprises: a second interface die attached to the PCB, thesecond interface die including a second surface opposite to the PCB; anda second semiconductor die assembly attached to the second surface,wherein the second semiconductor die assembly includes: a second memorycontroller die having a third side and a fourth side opposite to thethird side; one or more second memory dies attached to the third side,the one or more second memory dies operatively coupled to the secondmemory controller die; and a second biodegradable structure attached tothe fourth side, the second biodegradable structure including theconductive material operatively coupled to the second memory controllerdie and the insulating material.
 18. The system of claim 17, wherein theone or more memory dies of the first semiconductor die assembly includedynamic random access memory (DRAM) dies, and wherein the one or moresecond memory dies of the second semiconductor die assembly includeNot-AND (NAND) memory dies.
 19. The system of claim 10, wherein theinterface die is a first interface die, the semiconductor die assemblyis a first semiconductor die assembly, and the system further comprises:a second interface die attached at a second sidewall of thebiodegradable structure of the first semiconductor die assembly, thesecond sidewall facing away from the PCB, wherein the second interfacedie includes a second surface opposite to the PCB; and a secondsemiconductor die assembly attached to the second surface, wherein thesecond semiconductor die assembly includes: a second memory controllerdie having a third side and a fourth side opposite to the third side;one or more second memory dies attached to the third side, the one ormore second memory dies operatively coupled to the second memorycontroller die; and a second biodegradable structure attached to thefourth side, the second biodegradable structure including the conductivematerial operatively coupled to the second memory controller die and theinsulating material.
 20. A system, comprising: a printed circuit board(PCB); an interface die attached to the PCB, the interface die having asurface opposite to the PCB; a first semiconductor die assembly attachedto the surface, wherein the first semiconductor die assembly includes: afirst memory controller die having a first side and a second sideopposite to the first side; one or more first memory dies attached tothe first side, the one or more first memory dies operatively coupled tothe first memory controller die; and a first biodegradable structureattached to the second side, the biodegradable structure including aconductive material operatively coupled to the first memory controllerdie and an insulating material, wherein both the conductive material andthe insulating material are biodegradable and configured to disintegratein a wet process; a biodegradable structure electrically coupled to theinterface die at the surface and vertically extended to a first heightgreater than a second height of the first semiconductor die assembly;and a second semiconductor die assembly attached to the biodegradablestructure at the first height, wherein the second semiconductor dieassembly includes: a second memory controller die having a third sideand a fourth side opposite to the third side; one or more second memorydies attached to the third side, the one or more second memory diesoperatively coupled to the second memory controller die; and a secondbiodegradable structure attached to the fourth side, the secondbiodegradable structure including the conductive material operativelycoupled to the second memory controller die and the insulating material.